Relation between crystal and magnetic structures of layered manganite La_{2-2cursive greek chi}Sr_{1+2cursive greek chi}Mn₂O₇ (0.30 ≤ cursive greek chi ≤ 0.50)

The magnetic phase diagram of La_{2-2cursive Greek chi}Sr_{1+2cursive Greek chi}Mn₂O₇ (0.30 ≤ cursive Greek chi ≤ 0.50) was reexamined from the point of view of the crystal structure, particularly the Jahn-Teller (JT) distortion Δ_JT of Mn-O₆ octahedra, i.e., the ratio of the averaged apical Mn-O bond length to the equatorial Mn-O bond length. We have found that Δ_JT decreases with increasing hole concentration cursive Greek chi, while the canting angle between neighboring planes continuously increases from 0° (planar ferromagnet: 0.32 ≤ cursive Greek chi ≤ 0.38) to 180° (A-type antiferromagnet (AFM): cursive Greek chi = 0.48). The dominance of the A-type AFM structure with the decrease of Δ_JT can be ascribed to the change in the e_g orbital state from d_{3z2-cursive Greek chi}2 to d_{cursive Greek chi2-y2}.